Movable root contact/pressure plate assembly for hydroponic system

Abstract

A hydroponic system for growing sweet potatoes and other root and tuber crops includes a growing channel incorporating a movable root contact/pressure plate assembly. The assembly consists of a flat, rigid PVC plate in which holes for inserting plants are drilled and a flexible vinyl film which is secured along the length of each side edge of the plate, by means of pressure fit connectors. The assembly is secured to the top edges of a growing channel, again by pressure fit connectors. The flexible film suspends the plate near and parallel to the bottom of the growing channel, with the flexibility of the film allowing upward movement of the plate within the channel as the plant roots grow. The assembly provides contact and pressure to the plant roots inside the growing channel thereby promoting enlargement of the roots. This enlargement causes the assembly to move upwardly, thereby maintaining the desired pressure conditions during growth. A suitable nutrient solution is supplied in the growing channel.

What is claimed is: 
     
       1. A method for growing storage root crops, comprising: supplying liquid nutrient to a plant-growing container;   supporting root crop plants above said liquid nutrient, said plants having at least some roots capable of developing into storage roots extending into contact with said nutrient solution;   exerting a predetermined, continuous, growth-stimulating pressure on said roots capable of developing into storage roots while said roots are in contact with said nutrient and maintaining a substantially constant pressure thereon throughout the growth period thereof to thereby stimulate and promote storage root growth.   
     
     
       2. The method of claim 1, wherein the step of supporting said root crop plants includes supporting said plants in a hydroponic system including a nonaggregate culture medium. 
     
     
       3. The method of claim 2, wherein the step supplying liquid nutrient includes causing nutrient to flow through said plant-growing container. 
     
     
       4. The method of claim 2, wherein the step of exerting a growth-stimulating pressure includes applying an external compressive pressure to said storage roots. 
     
     
       5. The method of claim 4, further including providing a controlled environment for said storage root crops in said hydroponic system. 
     
     
       6. A method for growing sweet potatoes, comprising: supporting sweet potato plants having storage roots in a controlled-environment, aggregate-free hydroponic system including a liquid nutrient supply;   positioning said plants to cause said plant storage roots to extent into contact with said liquid nutrient;   applying an external, predetermined, compressive, growth-enhancing pressure only to said storage roots by compressing said storage roots against a hydroponic system container, and maintaining said pressure substantially constant throughout the growth of said storage roots, said pressure being sufficiently great to stimulate and promote storage root growth in excess of the storage root growth produced by such a hydroponic system in the absence of said growth-enhancing pressure.   
     
     
       7. A method for growing root crops hydroponically, comprising: supplying a nutrient solution to a plant growing channel;   suspending in said channel a root contact/pressure plate assembly, said assembly including a plate suspended above the bottom wall of said growing channel to form a root chamber, said assembly being suspended for vertical motion within the channel;   supporting plants to be grown through said plate with the roots of the plants extending below the plate into said nutrient solution;   initially locating said plate close to the bottom wall of said growing channel so that growth of the roots within said root chamber will bring the roots into contact with said plate;   exerting by means of said plate and plate assembly a growth-stimulating pressure on said roots while said roots are in contact with said plate to promote formation and growth of storage roots; and   maintaining growth-stimulating contact and pressure on said storage roots while allowing said plate assembly to move away from the bottom wall of said growing channel to accommodate root enlargement while providing continuing pressure thereon.   
     
     
       8. The method of claim 7, further including providing a controlled environment for said plants. 
     
     
       9. The method of claim 7, wherein the step of suspending said contact/pressure plate assembly comprises supporting said assembly on flexible, adjustable supports, whereby said plate is adjustable with respect to said growing channel and is movable by pressure exerted by the growth of storage roots in said growing channel. 
     
     
       10. The method of claim 7, wherein the step of suspending a root contact/pressure plate assembly includes suspending an assembly having a predetermined weight which is sufficient, when in contact with the storage roots of said plants, to constantly exert on said roots, said growth-stimulating pressure.